JSON to Go Struct Free Online Tool 2026

Last updated March 22, 2026

Example: Nested Objects

// Input JSON:
{
  "user": {
    "id": 1,
    "name": "Alice",
    "address": {
      "street": "123 Main St",
      "city": "New York",
      "zip": "10001",
      "country": "US"
    }
  }
}

// Generated Go structs:
type Root struct {
    User User `json:"user"`
}

type User struct {
    ID      int     `json:"id"`
    Name    string  `json:"name"`
    Address Address `json:"address"`
}

type Address struct {
    Street  string `json:"street"`
    City    string `json:"city"`
    Zip     string `json:"zip"`
    Country string `json:"country"`
}

Example: Arrays

// Input JSON:
{
  "users": [
    { "id": 1, "name": "Alice", "roles": ["admin", "editor"] },
    { "id": 2, "name": "Bob",   "roles": ["viewer"] }
  ],
  "total": 2
}

// Generated Go structs:
type Root struct {
    Users []User `json:"users"`
    Total int    `json:"total"`
}

type User struct {
    ID    int      `json:"id"`
    Name  string   `json:"name"`
    Roles []string `json:"roles"`
}

Example: API Response with Optional Fields

// Input JSON:
{
  "id": 1,
  "username": "alice",
  "email": "alice@example.com",
  "displayName": "Alice Smith",
  "bio": null,
  "avatarUrl": "https://example.com/avatar.jpg",
  "createdAt": "2024-01-15T14:30:00Z",
  "updatedAt": "2024-03-10T09:15:00Z"
}

// Generated Go struct (null fields use pointer types):
type Root struct {
    ID          int     `json:"id"`
    Username    string  `json:"username"`
    Email       string  `json:"email"`
    DisplayName string  `json:"displayName"`
    Bio         *string `json:"bio"`           // pointer — can be null
    AvatarURL   string  `json:"avatarUrl"`
    CreatedAt   string  `json:"createdAt"`
    UpdatedAt   string  `json:"updatedAt"`
}

Example: Ethereum API Response

// Input JSON (eth_getBlock response):
{
  "number": "0x12a05f2",
  "hash": "0xabc123...",
  "parentHash": "0xdef456...",
  "timestamp": "0x65a4b2c1",
  "gasLimit": "0x1c9c380",
  "gasUsed": "0x1234567",
  "transactions": [
    "0xtx1hash...",
    "0xtx2hash..."
  ],
  "miner": "0xmineraddress..."
}

// Generated Go struct:
type Block struct {
    Number       string   `json:"number"`
    Hash         string   `json:"hash"`
    ParentHash   string   `json:"parentHash"`
    Timestamp    string   `json:"timestamp"`
    GasLimit     string   `json:"gasLimit"`
    GasUsed      string   `json:"gasUsed"`
    Transactions []string `json:"transactions"`
    Miner        string   `json:"miner"`
}

Example: Complex Nested with Arrays of Objects

// Input JSON:
{
  "order": {
    "id": "ORD-001",
    "customer": { "id": 1, "name": "Alice" },
    "items": [
      {
        "product": { "id": 10, "name": "Widget", "price": 9.99 },
        "quantity": 2,
        "discount": 0.1
      }
    ],
    "total": 17.98,
    "status": "pending"
  }
}

// Generated Go structs:
type Root struct {
    Order Order `json:"order"`
}

type Order struct {
    ID       string   `json:"id"`
    Customer Customer `json:"customer"`
    Items    []Item   `json:"items"`
    Total    float64  `json:"total"`
    Status   string   `json:"status"`
}

type Customer struct {
    ID   int    `json:"id"`
    Name string `json:"name"`
}

type Item struct {
    Product  Product `json:"product"`
    Quantity int     `json:"quantity"`
    Discount float64 `json:"discount"`
}

type Product struct {
    ID    int     `json:"id"`
    Name  string  `json:"name"`
    Price float64 `json:"price"`
}

Example: Using the Generated Struct

// Generated struct for a user API response:
type User struct {
    ID    int    `json:"id"`
    Name  string `json:"name"`
    Email string `json:"email"`
}

// Unmarshal JSON into struct:
package main

import (
    "encoding/json"
    "fmt"
)

func main() {
    data := []byte(`{"id":1,"name":"Alice","email":"alice@example.com"}`)
    
    var user User
    if err := json.Unmarshal(data, &user); err != nil {
        panic(err)
    }
    
    fmt.Println(user.Name)  // → Alice
    fmt.Println(user.Email) // → alice@example.com
}

// Marshal struct back to JSON:
jsonBytes, _ := json.Marshal(user)
fmt.Println(string(jsonBytes))
// → {"id":1,"name":"Alice","email":"alice@example.com"}

omitempty Tag Option

// Without omitempty (zero values are included in JSON output):
type User struct {
    ID    int    `json:"id"`
    Name  string `json:"name"`
    Bio   string `json:"bio"`
}
// json.Marshal({ID: 1, Name: "Alice"}) → {"id":1,"name":"Alice","bio":""}

// With omitempty (zero values are omitted from JSON output):
type User struct {
    ID    int    `json:"id"`
    Name  string `json:"name"`
    Bio   string `json:"bio,omitempty"`
}
// json.Marshal({ID: 1, Name: "Alice"}) → {"id":1,"name":"Alice"}

Paste your JSON to generate Go structs instantly. The converter handles nested objects, arrays, null values, and snake_case to PascalCase name conversion automatically.

// Input JSON:
{
  "id": 42,
  "name": "Alice Smith",
  "email": "alice@example.com",
  "age": 30,
  "active": true,
  "score": 98.5
}

// Generated Go struct:
type Root struct {
    ID     int     `json:"id"`
    Name   string  `json:"name"`
    Email  string  `json:"email"`
    Age    int     `json:"age"`
    Active bool    `json:"active"`
    Score  float64 `json:"score"`
}